Uso do biocarvão de caroços de umbu na produção de mudas de Mulungu
wandalla brenda
UFERSA
Narjara Walessa Nogueira
Universidade Federal Rural do Semi-árido
Jefferson Araújo da Silva
Universidade Federal Rural do Semi-árido
Felipe Loan Barreto de Araújo
Universidade Federal Rural do Semi-árido
Romulo Magno Oliveira de Freitas
Instituito Federal do Rio Grande do Norte
Palavras-chave: Biocarvão; Spondias tuberosa; Erythrina velutina.
Resumo
The National Solid Waste Policy establishes responsibility throughout the product life cycle and mandates environmentally appropriate final disposal, prioritizing reuse, recycling, composting, recovery, and energy utilization, with specific operational standards aimed at preventing harm to human health and the environment. As with all production processes, the fruit pulp agroindustry generates a large volume of organic waste. Therefore, proper disposal is necessary, and one environmentally sound alternative in accordance with legislation is the conversion of this waste into biochar. This study aimed to evaluate the use of biochar derived from umbu seeds (Spondias tuberosa Arr. Cam.) as a soil conditioner in the production of mulungu (Erythrina velutina Willd) seedlings. The research was conducted in a greenhouse at the Federal Rural University of the Semi-Arid (UFERSA), Mossoró campus. The umbu seeds underwent a pyrolysis process in an adapted furnace for approximately two hours. The biochar was mixed with soil at rates of 0, 15, 30, 45, and 60 t·ha⁻¹ and used as a substrate for mulungu seedlings. Before sowing, mechanical clipping opposite the hilum was performed as a pre-germination treatment, and seeds were sown in 280 mL tubes. On the 11th day, thinning was carried out, leaving one plant per container. The seedlings were irrigated with tap water (0.5 dS·m⁻¹), and the experiment lasted for 60 days. Subsequently, growth and biomass analyses were performed, including shoot length (SL), root length (RL), stem diameter (SD), leaf dry mass (LDM), stem dry mass (SDM), shoot dry mass (ShDM), root dry mass (RDM), total dry mass (TDM), robustness index (RI), and Dickson quality index (DQI). Data were subjected to ANOVA and compared using Tukey’s test at 5%, and when significant, regression curves were generated using SigmaPlot®. Shoot length showed continuous growth with increasing doses, while root length was not affected by the applied doses. Stem diameter increased up to the intermediate rate of 30 t·ha⁻¹ and decreased thereafter. Leaf dry mass increased progressively with higher doses, whereas stem dry mass and shoot dry mass increased up to intermediate doses (30–40 t·ha⁻¹) and decreased at higher doses. Root dry mass and total dry mass showed a continuous growth trend, reaching the highest values at the highest doses. The Dickson quality index achieved the best performance at intermediate doses. Overall, the doses of 30–40 t·ha⁻¹ were the most favorable for balanced growth and seedling quality, while the dose of 60 t·ha⁻¹ promoted greater biomass accumulation. Therefore, incorporating umbu seed biochar had positive effects on the production of mulungu seedlings, with recommended application rates between 30 and 45 t·ha⁻¹.